Submission #693197

# Submission time Handle Problem Language Result Execution time Memory
693197 2023-02-02T13:02:41 Z sharaelong Ancient Books (IOI17_books) C++17
12 / 100
34 ms 59056 KB
#include "books.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;

struct DisjointSet {
    int n;
    vector<int> parent, rank;
    DisjointSet(int _n) : n(_n) {
        parent.resize(n);
        iota(parent.begin(), parent.end(), 0);
        rank.resize(n, 0);
    }

    int find(int u) {
        return parent[u] = (u == parent[u] ? u : find(parent[u]));
    }

    void merge(int u, int v) {
        u = find(u); v = find(v);
        if (u == v) return;
        if (rank[u] > rank[v]) swap(u, v);
        parent[u] = v;
        if (rank[u] == rank[v]) ++rank[v];
    }
};

struct FenwickTree {
    vector<int> tree;
    FenwickTree(int size) {
        tree.resize(size+1, 0);
    }

    int sum(int pos) {
        int ret = 0;
        for (int i=pos+1; i>0; i &= (i-1)) ret += tree[i];
        return ret;
    }

    void add(int pos, int val) {
        for (int i=pos+1; i<tree.size(); i+=(i & -i)) tree[i] += val;
    }
};

const int MAX_N = 1e6 + 1;
const ll INF = 4e18;

DisjointSet dsu(MAX_N);
FenwickTree fen(MAX_N);
bool visited[MAX_N];
vector<int> cycle[MAX_N];
vector<int> adj[MAX_N];

void dfs(int here, int parent = -1) {
    // cout << here << ' ' << parent << ": ";
    // for (int x:cycle[here]) cout << x << ' ';
    // cout << endl;
    bool merged = false;
    if (parent != -1) {
        parent = dsu.find(parent);
        int mn = *min_element(cycle[here].begin(), cycle[here].end());
        int mx = *max_element(cycle[here].begin(), cycle[here].end());
        if (fen.sum(mx) - fen.sum(mn) > 0) {
            dsu.merge(here, parent);
            for (int x: cycle[here]) fen.add(x, 1);
            if (cycle[here].size() > cycle[parent].size()) swap(cycle[here], cycle[parent]);
            for (int x: cycle[here]) cycle[parent].push_back(x);
            merged = true;
        }
    }
    
    if (!merged) {
        for (int x: cycle[here]) assert(fen.sum(x)-fen.sum(x-1) == 0);
        for (int x: cycle[here]) fen.add(x, 1);
    }
    for (int there: adj[here]) {
        dfs(there, here);
    }
    if (!merged) {
        for (int x: cycle[dsu.find(here)]) fen.add(x, -1);
        for (int x: cycle[dsu.find(here)]) assert(fen.sum(x)-fen.sum(x-1)==0);
    }
}

ll minimum_walk(vector<int> p, int s) {
    int n = p.size();
    vector<pair<pii, int>> range;
    ll jump_len = 0;
    for (int i=0; i<n; ++i) {
        if (!visited[i]) {
            int l = i, r = i;
            jump_len += abs(i-p[i]);
            visited[i] = true;
            int x = p[i];
            while (x != i) {
                l = min(l, x);
                r = max(r, x);
                jump_len += abs(x-p[x]);
                visited[x] = true;
                dsu.merge(x, i);
                x = p[x];
            }
            if (l < r) range.push_back({ { l, r }, i });
        }
    }
    
    sort(range.begin(), range.end());
    set<pii> intv_set;
    for (int i=0; i<range.size(); ++i) {
        auto[l, r] = range[i].first;
        auto it = intv_set.lower_bound({l, 0});
        while (it != intv_set.end() && (*it).first < r) {
            dsu.merge(range[i].second, (*it).second);
            it = next(it);
        }
        intv_set.insert({ r, range[i].second });
    }
    
    vector<pair<pii, int>> dfs_order;
    for (int i=0; i<n; ++i) cycle[dsu.find(i)].push_back(i);
    for (int i=0; i<n; ++i) {
        if (dsu.find(i) == i && cycle[i].size() >= 2) {
            dfs_order.push_back({ { cycle[i][0], cycle[i].back() }, i });
        }
    }
    sort(dfs_order.begin(), dfs_order.end());
    
    vector<pii> st;
    vector<int> roots;
    for (int i=0; i<dfs_order.size(); ++i) {
        while (!st.empty() && st.back().first < dfs_order[i].first.first) st.pop_back();
        if (!st.empty()) adj[st.back().second].push_back(dfs_order[i].second);
        else roots.push_back(dfs_order[i].second);
        st.push_back({ dfs_order[i].first.second, dfs_order[i].second });
    }
    for (int r: roots) dfs(r);

    ll ans = 0;
    for (int i=0; i<roots.size(); ++i) {
        int r = dsu.find(roots[i]);
        sort(cycle[r].begin(), cycle[r].end());
        // for (int x: cycle[r]) cout << x << ' ';
        // cout << endl;
        if (i > 0) ans += cycle[r][0];
        if (i+1 < roots.size()) ans -= cycle[r].back();
        
        if (cycle[r][0] <= s && s <= cycle[r].back()) {
            ll tmp = INF;
            for (int x: cycle[r]) tmp = min(tmp, (ll)abs(x-s));
            ans += tmp;
        }
    }
    if (!roots.empty()) {
        if (s < cycle[dsu.find(roots[0])][0]) ans += cycle[dsu.find(roots[0])][0]-s;
        if (s > cycle[dsu.find(roots.back())].back()) ans += s-cycle[dsu.find(roots.back())].back();
    }
    return jump_len + 2ll * ans;
}

Compilation message

books.cpp: In member function 'void FenwickTree::add(int, int)':
books.cpp:42:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |         for (int i=pos+1; i<tree.size(); i+=(i & -i)) tree[i] += val;
      |                           ~^~~~~~~~~~~~
books.cpp: In function 'll minimum_walk(std::vector<int>, int)':
books.cpp:110:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<std::pair<int, int>, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  110 |     for (int i=0; i<range.size(); ++i) {
      |                   ~^~~~~~~~~~~~~
books.cpp:131:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<std::pair<int, int>, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  131 |     for (int i=0; i<dfs_order.size(); ++i) {
      |                   ~^~~~~~~~~~~~~~~~~
books.cpp:140:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  140 |     for (int i=0; i<roots.size(); ++i) {
      |                   ~^~~~~~~~~~~~~
books.cpp:146:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  146 |         if (i+1 < roots.size()) ans -= cycle[r].back();
      |             ~~~~^~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 30 ms 58964 KB Output is correct
2 Correct 32 ms 58956 KB Output is correct
3 Correct 27 ms 58948 KB Output is correct
4 Correct 27 ms 58976 KB Output is correct
5 Correct 28 ms 58940 KB Output is correct
6 Correct 27 ms 58964 KB Output is correct
7 Correct 30 ms 58936 KB Output is correct
8 Correct 32 ms 58964 KB Output is correct
9 Correct 29 ms 59000 KB Output is correct
10 Correct 31 ms 58932 KB Output is correct
11 Correct 30 ms 58960 KB Output is correct
12 Correct 29 ms 58964 KB Output is correct
13 Correct 28 ms 59024 KB Output is correct
14 Correct 29 ms 58940 KB Output is correct
15 Correct 28 ms 58896 KB Output is correct
16 Correct 28 ms 58992 KB Output is correct
17 Correct 28 ms 59012 KB Output is correct
18 Correct 28 ms 58948 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 30 ms 58964 KB Output is correct
2 Correct 32 ms 58956 KB Output is correct
3 Correct 27 ms 58948 KB Output is correct
4 Correct 27 ms 58976 KB Output is correct
5 Correct 28 ms 58940 KB Output is correct
6 Correct 27 ms 58964 KB Output is correct
7 Correct 30 ms 58936 KB Output is correct
8 Correct 32 ms 58964 KB Output is correct
9 Correct 29 ms 59000 KB Output is correct
10 Correct 31 ms 58932 KB Output is correct
11 Correct 30 ms 58960 KB Output is correct
12 Correct 29 ms 58964 KB Output is correct
13 Correct 28 ms 59024 KB Output is correct
14 Correct 29 ms 58940 KB Output is correct
15 Correct 28 ms 58896 KB Output is correct
16 Correct 28 ms 58992 KB Output is correct
17 Correct 28 ms 59012 KB Output is correct
18 Correct 28 ms 58948 KB Output is correct
19 Correct 29 ms 58928 KB Output is correct
20 Correct 31 ms 58960 KB Output is correct
21 Correct 28 ms 59056 KB Output is correct
22 Correct 32 ms 59012 KB Output is correct
23 Correct 29 ms 58992 KB Output is correct
24 Correct 33 ms 59056 KB Output is correct
25 Correct 34 ms 58964 KB Output is correct
26 Incorrect 30 ms 58924 KB 3rd lines differ - on the 1st token, expected: '12988', found: '13018'
27 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 30 ms 58964 KB Output is correct
2 Correct 32 ms 58956 KB Output is correct
3 Correct 27 ms 58948 KB Output is correct
4 Correct 27 ms 58976 KB Output is correct
5 Correct 28 ms 58940 KB Output is correct
6 Correct 27 ms 58964 KB Output is correct
7 Correct 30 ms 58936 KB Output is correct
8 Correct 32 ms 58964 KB Output is correct
9 Correct 29 ms 59000 KB Output is correct
10 Correct 31 ms 58932 KB Output is correct
11 Correct 30 ms 58960 KB Output is correct
12 Correct 29 ms 58964 KB Output is correct
13 Correct 28 ms 59024 KB Output is correct
14 Correct 29 ms 58940 KB Output is correct
15 Correct 28 ms 58896 KB Output is correct
16 Correct 28 ms 58992 KB Output is correct
17 Correct 28 ms 59012 KB Output is correct
18 Correct 28 ms 58948 KB Output is correct
19 Correct 29 ms 58928 KB Output is correct
20 Correct 31 ms 58960 KB Output is correct
21 Correct 28 ms 59056 KB Output is correct
22 Correct 32 ms 59012 KB Output is correct
23 Correct 29 ms 58992 KB Output is correct
24 Correct 33 ms 59056 KB Output is correct
25 Correct 34 ms 58964 KB Output is correct
26 Incorrect 30 ms 58924 KB 3rd lines differ - on the 1st token, expected: '12988', found: '13018'
27 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 29 ms 59012 KB 3rd lines differ - on the 1st token, expected: '3304', found: '3590'
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 30 ms 58964 KB Output is correct
2 Correct 32 ms 58956 KB Output is correct
3 Correct 27 ms 58948 KB Output is correct
4 Correct 27 ms 58976 KB Output is correct
5 Correct 28 ms 58940 KB Output is correct
6 Correct 27 ms 58964 KB Output is correct
7 Correct 30 ms 58936 KB Output is correct
8 Correct 32 ms 58964 KB Output is correct
9 Correct 29 ms 59000 KB Output is correct
10 Correct 31 ms 58932 KB Output is correct
11 Correct 30 ms 58960 KB Output is correct
12 Correct 29 ms 58964 KB Output is correct
13 Correct 28 ms 59024 KB Output is correct
14 Correct 29 ms 58940 KB Output is correct
15 Correct 28 ms 58896 KB Output is correct
16 Correct 28 ms 58992 KB Output is correct
17 Correct 28 ms 59012 KB Output is correct
18 Correct 28 ms 58948 KB Output is correct
19 Correct 29 ms 58928 KB Output is correct
20 Correct 31 ms 58960 KB Output is correct
21 Correct 28 ms 59056 KB Output is correct
22 Correct 32 ms 59012 KB Output is correct
23 Correct 29 ms 58992 KB Output is correct
24 Correct 33 ms 59056 KB Output is correct
25 Correct 34 ms 58964 KB Output is correct
26 Incorrect 30 ms 58924 KB 3rd lines differ - on the 1st token, expected: '12988', found: '13018'
27 Halted 0 ms 0 KB -